Over the past two days, Musk has bought 72,500 shares in Tesla, when shares were trading at $342-$347, according to an SEC filing. The total purchase is worth about $24.9 million.

Tesla has an abundance of skeptics, but Musk has continued to fork over cash for shares in the electric car maker. Back in early May, Musk bought 33,000 Tesla shares, then worth about $10 million. Shares were trading just below $300 at that point.

Musk is Tesla's largest shareholder. He now owns about 33.7 million shares of Tesla, a roughly 19 percent slice of all outstanding shares.

Musk made his purchases shortly after Tesla said it will cut about 9 percent of its workforce of 46,000 employees, in salaried roles outside vehicle production. The company is trying to improve efficiency and profitability as it continues the continually delayed and often struggling production ramp of its Model 3 sedan.

The company is still burning through billions in cash, and has faced challenges on several fronts, including labor disputes, a number of executive departures, and investigations into the role is Autopilot driver assistance system has played in some high-profile crashes.